1. Field of the Invention
The present invention relates to a valve drive mechanism and, more particularly, to a valve drive mechanism for an internal combustion engine.
2. Description of the Related Art
One type of valve drive mechanism for an internal combustion engine comprises a camshaft, which drives an intake and/or exhaust valve to open and close through a rocker arm. A swing member or rocking member is positioned between the rocker arm and the camshaft. The swing member is rocked back and forth by a rotating cam that is provided on the camshaft. A cam surface on the swing member comes into contact with a cam surface on the rocking arm. Thus, when the swing member is rocked or swung back and forth, this motion is transferred to the rocker arm causing it to be rocked back and forth. This reciprocal motion causes the rocker arm to press against the intake and/or exhaust valve to open/close the valve. JP-A-H7-063023 describes such a valve mechanism.